Storage phosphor imaging systems are known. In one such system, a storage phosphor is exposed to an x-ray image of an object, such as a body part of a patient, to record a latent x-ray image in the storage phosphor. The latent x-ray image is read out by stimulating the storage phosphor with stimulating radiation. Upon stimulation, the storage phosphor releases emitted radiation of a particular wavelength. To produce a signal useful in electronic image processing, the storage phosphor is scanned, for example, by a laser beam deflected by an oscillating or rotating scanning mirror or by a rotation hologon. The emitted radiation from the storage phosphor is reflected by a collector and detected by a photodetector, such as a photomultiplier, to produce an electronic x-ray image signal. The x-ray image signal can then be viewed as a visual image produced by a softcopy display device, such as a CRT or LCD display, or a hardcopy display device, such as a x-ray film printer (laser printer, CRT printer, thermal printer). U.S. Pat. No. Re. 31,847, issued Mar. 12, 1985, inventor Luckey discloses a storage phosphor system. The reader is often referred to as a computed radiography (CR) reader.
The storage phosphor can be disposed on a medium. Such a medium can be flexible, semi-flexible, semi-rigid, or rigid, and can be configured as a sheet or other substantially planar arrangement. When the storage phosphor is being processed/scanned/read/exposed by the storage phosphor processor/reader, it is important that the position of the storage phosphor be controlled so as to not introduce any artifacts in the processed image.
Accordingly, there exists a need to control a medium as it is being transported through an optical imaging system. In Applicant's particular application, there exists a need to control a storage phosphor medium in a storage phosphor reader.